Fork Spring Advice

[DeweyIsgod]

I've read a lot from searching and want to upgrade my front fork springs. A full upgrade isn't in the budget at the moment (although might be in the future).

From the research I've done, I'm between:

A) Race Tech replacement springs (linear option) that are weight specific

https://racetech.com/ProductSearch/2/Yamaha/FJR1300/2003-09

and

B) HyperPro Progressive Springs

https://epmperf.com/hyperpro-springs.htm

Can anyone elaborate on the benefits and detriments of one technology over the other? Specifically questions include:

1) Is the Hyperpro used if you later on do the full upgrade of the valving?

2) I'm assuming the preload is adjusted to set the sag on the progressive spring so that you're starting in the correct portion of the spring rate curve. Is that the case or is there something else that makes one spring good for all rider weights?

As background, I've got 43,000 miles on my 2006. I have had a penske 8893 on the rear for 3 months and 2,000 miles. I live in Houston, so most of my riding is in straight lines although I do like to be a little spirited when I occasionally get to curvier roads. I'm a 230 lb rider and ride with a 130 lb passenger less than 5% of the time.

 

[scotlings8]

I have the HyperPro Springs front and rear in my 09. It was literally the best farkle I have done to date. The bike does not dive anymore during braking, and the handling is much better. The ride is a bit stiff now, but i would much prefer that over horrible handling. When i do ride with my wife the progressive spring sucks up the extra weight very well, as I no longer have the "soft/hard" lever. There are a lot of different threads on here comparing both types though. So I would do your homework.

 

[Fred W]

I'm working through this on my own bike right now. Which, if you know anything about me you's know means, I'm making the most possible mistakes along the way.

My bike was bought used with a stock rear shock and an upgraded set of fork springs. What spring rating they are I do not know for sure, but the sag measurements are 25mm bike sag, 36 mm rider sag with the preload set to zero (IOW pretty damn stiff).

I later bought a used Penske shock (which had a few miles on it) for a good price and put that on the bike. It had an 800 lb/inch spring on it, which seemed to work OK for both solo and two up (I am 225 lbs, wife 100 lbs). I sent my Penske shock in for service at GP suspensions in WA, since it had probably 30k miles on it between me and the original owner. They recommended I up the spring rate on the rear shock to a 900, and they recommended 1.05 kg/mm springs for the forks.

I've got the shock back and installed and it feels pretty damn stiff on the back. I checked the sag with tyhe help of my wife and I'm getting a reasonable 41mm but that is with very little spring preload. I can't put anything into the compression damping with out the rear end feeling like a hardtail (harsh). And it is taking a whole lot of rebound damping to keep it in check after any bumps. I am starting to think maybe they got the spring wrong.

I will wait until after I swap the springs up front from the unknowns to the 1.05's (I think I might have 1.1's in there now based on the sag numbers) and upgrade the fork damping with their compression and rebound re-valve kits and see how that all feels together, but I think I may be going back down to the 800 lb rear.

I wouldn't fool around with progressive springs. It just makes it much harder to dial in the right spring rates and get the right amount of sag (which affects all of your steering angles)

 

[ahchiu]

I have the HyperPro Springs front and rear in my 09. It was literally the best farkle I have done to date. The bike does not dive anymore during braking, and the handling is much better. The ride is a bit stiff now, but i would much prefer that over horrible handling. When i do ride with my wife the progressive spring sucks up the extra weight very well, as I no longer have the "soft/hard" lever. There are a lot of different threads on here comparing both types though. So I would do your homework.

+1, Happy with HyperPro setup

 

[DeweyIsgod]

Fred - I'm very similar to your weight and the Race Tech calculator suggested a 1.01 kg/mm. They sell a 1.0 and a 1.1 - no 1.05. Can I inquire what the 1.05 from GP set you back (and does it need a washer kit to fit)?

 

[ULEWZ]

I bought the Sonic 1.0 spring kit and I am 180 lbs. I would recommend the 1.1 springs for your weight as I don't trust the RT spring calculator. The kit comes with a new spacer to be cut easily with a tube cutter. There washers are required, one below the spring, one on top of the spring, and one on top of the spacer. You will only have two currently installed. You can reuse the stock thin neck spacer if you only want to use 2 washers.

The third washer is required with the sonic spacer as the mouth of the spacer is too wide and will fit around the fork cap, making adjustments useless. As for progressive springs, I have never used them, but hear they work great for cruising, but not so much for real serious road work. Ducking for cover now.

I assume the spring installed on your Penske is linear also? If so, I would stick with the same on the forks.

 

[RiderX]

+1. According to their lead tech at RT HQ in Corona, the calculator isn't so good for FJRs (so fix it!). It appears nothing has changed on that site (except their sponsorship deals) in several years.

They told me 1.1 is the minimum they will do (if they are doing the work) based on experience with FJR Gen II. (unless you are really <ahem> small). They wanted to do 1.2 kg/mm for me when they saw the dash shelf and ram mount frezy. Very wonderful, but can only compare to stock.

 

[Fred W]

Fred - I'm very similar to your weight and the Race Tech calculator suggested a 1.01 kg/mm. They sell a 1.0 and a 1.1 - no 1.05. Can I inquire what the 1.05 from GP set you back (and does it need a washer kit to fit)?

I bought the springs (along with some other goodies) from GP in this winter's group buy. The regular (non-GB) price for their springs is $105. They come with a flange on the bottom end of the spring.

The proprietary black thing they call "spring buffers" for the top is an extra $29.50

I bought the Sonic 1.0 spring kit and I am 180 lbs. I would recommend the 1.1 springs for your weight as I don't trust the RT spring calculator. The kit comes with a new spacer to be cut easily with a tube cutter. There washers are required, one below the spring, one on top of the spring, and one on top of the spacer. You will only have two currently installed. You can reuse the stock thin neck spacer if you only want to use 2 washers.The third washer is required with the sonic spacer as the mouth of the spacer is too wide and will fit around the fork cap, making adjustments useless. As for progressive springs, I have never used them, but hear they work great for cruising, but not so much for real serious road work. Ducking for cover now.

I assume the spring installed on your Penske is linear also? If so, I would stick with the same on the forks.

If you don't mind telling, what are your forks' sag numbers (bike load only and fully rider loaded) with those 1.0kg Sonics? I'm trying to figure out what I have in there now on mine. I know they're Sonic, but not sure which ones. Don't remember seeing anything scribed on the spring ends when I flushed the forks out the last time. I mentioned my sag numbers earlier (25mm / 36mm) and that is with the preload adjusters fully extended (out)

+1. According to their lead tech at RT HQ in Corona, the calculator isn't so good for FJRs (so fix it!). It appears nothing has changed on that site (except their sponsorship deals) in several years.
They told me 1.1 is the minimum they will do (if they are doing the work) based on experience with FJR Gen II. (unless you are really <ahem> small). They wanted to do 1.2 kg/mm for me when they saw the dash shelf and ram mount frezy. Very wonderful, but can only compare to stock.

I'm finding that you have to be somewhat careful when talking to these suspension people. They all want to set you up like you'll be riding on a track. I won't be. In fact the beat-up roads in the Northeast are about the farthest from track conditions that you'd ever encounter. Yeah, it's nice for handling and cornering to have a tightly sprung bike when the roads are smooth, but when they aren't you want the wheel to follow the full irregularities in the road without disturbing the bike's attitude. That will require a little softer springing that full on race spec.

 

[Afast03nNJ]

I did the Hyper-Pro on my 03, front and rear on a new OE shock. It was a night and day difference, best bang for your buck mod I ever did.

 

[ULEWZ]

If you don't mind telling, what are your forks' sag numbers (bike load only and fully rider loaded) with those 1.0kg Sonics? I'm trying to figure out what I have in there now on mine. I know they're Sonic, but not sure which ones. Don't remember seeing anything scribed on the spring ends when I flushed the forks out the last time. I mentioned my sag numbers earlier (25mm / 36mm) and that is with the preload adjusters fully extended (out)

My fork springs are scribed on the top 1.0. I ended up with 32mm of sag, but I don't remember what the bike load sag was. I will check later. That is with 4 inch spacers and 3 washers. As you know, you can change the sag with different size spacers, so what size are your spacers?

I will also remove 36cc of fluid as I went with racetechs recommendation of 110mm air gap which is to high. I will go to the GP recommendation of 130mm. That will entail removing 36cc of fluid. The forks are 48mm across and I want to drop the fluid level 20mm, so doing the math yields 36205 cubic mm. To convert to cubic centimeters (cc), divide by 1000, so approx 36cc will need to be removed. 9cc per 5mm of drop. Why is this handy, because I can remove fluid without taking my fork springs out using this method (my syringe is graduated in cc). Yes I know that is the OD and not the ID, but it is close enough me thinks.

 

[Fred W]

If you don't mind telling, what are your forks' sag numbers (bike load only and fully rider loaded) with those 1.0kg Sonics? I'm trying to figure out what I have in there now on mine. I know they're Sonic, but not sure which ones. Don't remember seeing anything scribed on the spring ends when I flushed the forks out the last time. I mentioned my sag numbers earlier (25mm / 36mm) and that is with the preload adjusters fully extended (out)

My fork springs are scribed on the top 1.0. I ended up with 32mm of sag, but I don't remember what the bike load sag was. I will check later. That is with 4 inch spacers and 3 washers. As you know, you can change the sag with different size spacers, so what size are your spacers?

I will also remove 36cc of fluid as I went with racetechs recommendation of 110mm air gap which is to high. I will go to the GP recommendation of 130mm. That will entail removing 36cc of fluid. The forks are 48mm across and I want to drop the fluid level 20mm, so doing the math yields 36205 cubic mm. To convert to cubic centimeters (cc), divide by 1000, so approx 36cc will need to be removed. 9cc per 5mm of drop. Why is this handy, because I can remove fluid without taking my fork springs out using this method (my syringe is graduated in cc). Yes I know that is the OD and not the ID, but it is close enough me thinks.

Thanks for the info. I'll recheck for scribed marks on mine. Maybe I just missed it. I do not know the spacer length (didn't measure it yet) but I will when I get in there. Might be able to get to do this work over this weekend. I'll report back whatever I find.

I know that with the preload adjusters all the way out the caps just barely compress the spring at all when you screw them in, and the bike's weight (~270 kg / 2) drops the forks down 25mm.

I suspect that my springs are at least 1.1 kg/mm as my static (no rider) sag is 25mm and when I jump on (~ +100 kg / 2) it only moves another 11 mm.

 

[ULEWZ]

Here is what I measured today with no gear by my self using a zip tie:

Hanging sag: 5-10/16 in.

Rider sag (no gear): 4-6/16 in.

Free sag, no rider: 4-12/16 (3/4) in.

 

[RaYzerman19]

I would go straight rate springs, not progressive. IMHO, Race Tech likes things a little stiffer than most, GP maybe recommends a bit soft. My RT rear shock was stiff when I got it, had to back the collar off a fair bit. Front springs on the other hand, I think they are bang on. Currently running 1.0 for 220 lbs., sag is at 35 with the preload pretty much set in the middle. Perfect for me. IF you need more preload, you can add washers or make new spacers. Springs too strong will always be too strong as Fred has found out.

 

[LAF]

I have Traxxion's Omni 1.1 in my 10. I love them. I am 214 in street cloths and in gear about 230. I am very happy with the ride. My spacer came cut to my weight, the oil level is very much lower then stock recommendations and I used Traxxions recommended oil. Also have Spring Buffers in there. I am wondering on oil levels and spacer lengths being a bit of an issue? Like I said I gave Lee at Traxxion my weight and riding style and I described it as spirited. The Pensky rear shock and the springs went in no issues and I have been in love with the ride ever since. I can go very stiff in the twisties and soften it up for long distance slab. It really is a wonderful set up for me. I am not sure what type of spring they are but the Omni springs do work for me over a wide range of riding conditions and adjust with very few clicks on any adjustment. I am pretty sure the oil weight was 7.

P83Y-FJR1300-2 Model 8983 '06-'10 Yamaha FJR1300, Shock Only,
Component
1 775.00 775.00T
SSH6x850 Shock Spring, Hyperco 6x850 (Suggested Retail $99.95) 1 99.95 99.95T
PD Traxxion Dynamics Parts Discount (10% off Retail for
FJR Owners)
-87.50 -87.50
SRB-FJR-1 Shock Reservoir Bracket, 06-09 FJR (Suggested Retail
$12.95)
1 10.00 10.00T
VSS6 6" Vented Shock Sock (Suggested Retail $16.95) 1 14.95 14.95T
OMNI1.10 Traxxion Dynamics Fork Spring Kit, OMNI x1.10
(Suggested Retail Price $109.95)
1 109.95 109.95T
FSBK11 Fork Spring Buffer Kit 11mm, used with Omni Springs.
(Suggested Retail $14.95)
1 14.95 14.95T
DROIL10 Fork Oil, 10 wt 2 9.95 19.90T
FRT Shipping/Handling/Insurance (Estimate Only, actual
shipping cost may be more or less)
20.00 20.00

 

[road runner]

I've got 1.1 in front and 900 in back. I can adjust the sag on both front and rear to go from 40mm to 50mm rider sag. I'm very happy with this set-up, because it can be adjusted for anything. Oh yeah, I'm 200 w/o gear on, have a Givi truck on, and usually carry 5-10 lbs of stuff.

I usually run 43mm front, and 40mm rear for combat mode. 48mm front and 45mm rear for plush. I know this is subjective (to each his own) just sayin what I like.

 

[Auron]

I'm 160 and Traxxion is recommending 1.1's Isn't that a little stiff? Even with the stock springs I'm not using all the available travel. Wouldn't 1.05's be better? Anyone weigh about what I do and what are you using?

Also, my Penske has a 850.

 

[JR'SFJR]

+1 on Hyper-pro, which I installed over 3 yrs ago.